Liberals start planning for Canning poll

A Melbourne Cup field is expected to contest preselection for the West Australian seat of Canning.

A by-election is expected in Canning within months after its Liberal MP Don Randall died of a suspected heart attack last month.

The 62-year-old former horse trainer was farewelled by about 500 people including Prime Minister Tony Abbott at a funeral service in Perth on Friday.

A senior WA Liberal source told AAP on Tuesday he expected up to 10 party members to nominate for preselection.

WA Liberal discussions on the preselection process are expected to start on Tuesday.

It will be up to the new Speaker of the federal parliament to announce the by-election date, once someone is elected to replace Bronwyn Bishop on Monday.

Mr Randall held the seat with a margin of almost 12 per cent.

The Liberal source said any attempt by federal members to parachute a "star candidate" into the seat would be resisted.

"The notion of someone being dropped in will be vigorously opposed," the Liberal said.

"There are 14 branches in Canning and they'll be looking for someone like Don, who comes from regional WA and understands regional issues."

The other complicating factor is the seat is expected to be split in two when a redistribution is completed in January.

Whoever wins the seat will have to choose whether to stay or contest the new seat when the federal election is held next year.